Effects of dietary aroclor 1254 and cyclopropene fatty acids on hepatic enzymes in rainbow trout.
Diets containing Aroclor 1254 (PCB); cyclopropene fatty acids (CPFA), and PCB plus CPFA were fed to rainbow trout (Salmo gairdneri) for 15 weeks to determine the effects on hepatic microsomal activities of ethoxyresorufin-O-deethylase, ethoxycoumarin-O-deethylase, and benzo(a)pyrene monooxygenase. Ethoxyresorufin-O-deethylase activity continued to increase to a level 77-fold higher than control at week 15. Ethoxycoumarin O-deethylase and benzo(a)pyrene monooxygenase activities increased to 7.1-fold and 47-fold over control at week 9, respectively. Cytochrome P-450 values remained approximately 2-fold above controls from week 5 through week 15. At weeks 1 and 3, cytochrome P-450 levels were not significantly different from control. Dietary CPFA significantly depressed ethoresorufin-O-deethylase and ethoxycoumarin-O-deethylase activities, but had no effect on benzo(a)pyrene monooxygenase activity. Ethoxyresorufin-O-deethylase, ethoxycoumarin-O-deethylase, nd benzo(a)pyrene monooxygenase activities in the combined PCB-CPFA-fed trout were significantly higher than in control- or CPFA-fed trout, and significantly lower than in PCB-fed trout. This is the first time dietary PCBs have been shown to induce the MFO system in rainbow trout. These results provide a possible explanation for the effects of dietary PCBs on the metabolism and expression of other chemical carcinogens.
D015660:7-Alkoxycoumarin O-Dealkylase; D016604:Aflatoxin B1; D000348:Aflatoxins / Q000633:toxicity; D000818:Animals; D001140:Aroclors / Q000633:toxicity*; D020111:Chlorodiphenyl (54% Chlorine); D004032:Diet; D005231:Fatty Acids, Unsaturated / Q000633:toxicity*; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008113:Liver Neoplasms / Q000139:chemically induced; D006899:Mixed Function Oxygenases / Q000032:analysis; D010105:Oxygenases / Q000032:analysis; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D012487:Salmonidae / Q000378:metabolism*; D014337:Trout / Q000378:metabolism*
D000348:Aflatoxins; D001140:Aroclors; D005231:Fatty Acids, Unsaturated; D020111:Chlorodiphenyl (54% Chlorine); D016604:Aflatoxin B1; D011078:Polychlorinated Biphenyls; D006899:Mixed Function Oxygenases; D010105:Oxygenases; D015660:7-Alkoxycoumarin O-Dealkylase